530grafix Posted January 8, 2008 Report Posted January 8, 2008 Alright I know this has been covered, but where is a good starting point for alky. I have EGN needles (these are the shees old carbs)mods are on my sig. Thanks to all. Quote
theshee Posted January 8, 2008 Report Posted January 8, 2008 I would start at 120 and work down. Better safe then sorry. There is a guy with 421 on alky up here tht runs 106's, but thats at 8500 feet. Quote
BigRed350x Posted January 8, 2008 Report Posted January 8, 2008 You will need to do or have the following things done, before you worry about jetting... Dump Tubes need to be drilled out to anywhere between .120 and .125 I go .120 to start with mine. DONT go bigger than .125" or your tubes are junk, and since you have PWK's you'd be screwed. So start off small and go bigger only if you need it. .120" is a good starting point. If you are running gravity feed go with a 3.8 or 3.9 needle valve and seat. If you run a pump go with 1.5 needle valves and seats. Drill/tap/install power jets. If your carbs are already converted for you here's a good starting point for jetting... 55 pilots .120 main jet (make sure your dump tubes are drilled to at least .120", a stock .113" main jet wont let a .120" flow...) EGN or EGQ needle on middle clip Power Jets opened all the way up to start. Start off WAY rich and work your way down. Watch your color rating on your plugs. Alky plugs read totally different than gas plugs. You might consider installing EGT sensors to keep an eye on things. Alky will run good even rich to the point your spewing fuel out the exhaust. It will really wake up when you get close, but you should also plan on going through at least 1 top end. Almost everyone does the first time on alky. At the first sign of any trouble shut it down and tow it home/load it up and check things out. DONT try and ride it back if it acts anything weird at all and you can save yourself a lot of trouble on rebuild later. Those jetting specs should get you close at any elevation, especially lower ones. I'm at 7200ft elevation and here's what I run... 52 pilot .110 main EGN needle on 2nd to top clip Power Jets around 1 or 2 turns out. I'm damn near close to the verge of being perfect but run mine a little rich. But remember I am at 7200ft elevation! Hope that helps you. - Jared Quote
BigRed350x Posted January 8, 2008 Report Posted January 8, 2008 Dammit Kiel you beat me to it. lol Quote
J-Madd Posted January 8, 2008 Report Posted January 8, 2008 I wasn't aware you had to change the needle seats!!??? On my 421 Cub with 39 mm pkws, I run dumps and mains drilled to .125, egn in the middle, 60 pilots. I can run the pjs all the way out and it still runs good. That was at 300 ft elevation and 80 - 90 degrees. I sometimes turn in the pjs a little to lean it out a little, but I always start the day with them all the way out. Quote
BigRed350x Posted January 9, 2008 Report Posted January 9, 2008 I wasn't aware you had to change the needle seats!!??? On my 421 Cub with 39 mm pkws, I run dumps and mains drilled to .125, egn in the middle, 60 pilots. I can run the pjs all the way out and it still runs good. That was at 300 ft elevation and 80 - 90 degrees. I sometimes turn in the pjs a little to lean it out a little, but I always start the day with them all the way out. Most stock PWK's come with 3.8 needle valves and seats. If you had something smaller I would change it out unless you run a pump, then a 1.5 is appropriate. Try a 58 pilot and it will help out your bottom end a little. 60 just seems huge to me. Quote
dajogejr Posted January 11, 2008 Report Posted January 11, 2008 Snomo pumper carbs have the seat pressed in...so I don't know if you can remove them on a gravity fed carb. .122 dumps, .120 mains, powerjets wide open, 55 pilots. red learned the hard way not to go bigger on your dumps than .125... You don't read alky plugs like gas, you read them by heat. There are two AWESOME Threads on Planet Sand with pictures on how to read, etc. I can tell you overall Cubs like to be flooded with alky to make good power. You can lean it out a little to get a bit more power, but....I'd call that the ragged edge...which I like to be on the safe side of. Here's the Plug heat reading threads, read away.... http://www.planetsand.com/forums/ubbthread.../784059/fpart/1 http://www.planetsand.com/forums/ubbthread.../757511/fpart/1 Quote
dajogejr Posted January 11, 2008 Report Posted January 11, 2008 I just read your sig... 8 paddle haulers on a 4 mil cub on alky??? You might as well put turf tamers on it for sand... If you have a fuel pump, are these carbs setup for a fuel pump??? I didn't know they made 38PWKs as pumper carbs.... Quote
Dave I. Posted January 11, 2008 Report Posted January 11, 2008 I just read your sig...8 paddle haulers on a 4 mil cub on alky??? You might as well put turf tamers on it for sand... If you have a fuel pump, are these carbs setup for a fuel pump??? I didn't know they made 38PWKs as pumper carbs.... His carbs are air strikers. He got them from theshee and were supposed to be 35s bored larger but I think they are actually 38s that are bored. He measured them and got a little less than 39mm from what I remember. There is no way possible to bore a 35 to a 39 thats what makes me think they were originally 38. I dont know if theshee set them up for a pump or not, or what has to be done to run a pump. Mine are gravity feed still. Quote
dajogejr Posted January 11, 2008 Report Posted January 11, 2008 At theshee's elevation, unless he was making a mile blasts, I don't think he needed a fuel pump and billet bowls... See what jetting he set them up for, however...I can assure you it's leaner than what you need at sea level, I know he rides at 7500 ft and up, BIG difference.... Quote
theshee Posted January 11, 2008 Report Posted January 11, 2008 Damn, sorry i didnt come back to this thread earlier. We ran these carbs on my bros mini twister. We got the carbs from majicmike who told is they would work on either gravity or a pump. He also said they were 35s bored to 38. I really have no idea other then what he told us about them. Wish I knew more about them but I really dont know. Quote
dajogejr Posted January 11, 2008 Report Posted January 11, 2008 Got it... Do yourself a favor, take the bowls off and look at the needle/seat, see if you can see a number, You can run a pump on a non-pumper set of needle and seat, but you have to adjust the floats different and they are VERY finicky.... Quote
theshee Posted January 11, 2008 Report Posted January 11, 2008 this is very frustrating to me just so you guys know. This is not the first time a part I got from him is NOT what he told me it was. I am very sorry for this mix up. Anything I can do to fix it let me know, I will take the heat and make it right. If you need different parts to make them work make sure you let me know how much they are so I can help out. Im not on this site to rip people off and sell bad parts, so I will do what ever is necessary to make this deal right. Quote
dajogejr Posted January 11, 2008 Report Posted January 11, 2008 I don't think there is any reason to apologize, just your willingness to help and make it right is enough... I've been dealt bad parts before, never actually used them...and made things right with who I sold them to. As with any bike/build, 530 just has to do a little measuring and research...and he'll be fine I'm sure... Quote
530grafix Posted January 20, 2008 Author Report Posted January 20, 2008 this is very frustrating to me just so you guys know. This is not the first time a part I got from him is NOT what he told me it was. I am very sorry for this mix up. Anything I can do to fix it let me know, I will take the heat and make it right. If you need different parts to make them work make sure you let me know how much they are so I can help out. Im not on this site to rip people off and sell bad parts, so I will do what ever is necessary to make this deal right. Kiel, thanks for the offer but no need, just having a hell of a time getting the idel right then it seem s that one side fires and the other does not. then after a quick rap it changes sides this is very agitating. The carbs Miked out At 37.96 close enough. I have a .120 main and a 55 pilot and egn needle in the middle, no pump...Thinking about goung back to gas. It ramn really good on gas. not a single problem. I m open to any other suggestions. And Dave, I just have not gotten any new paddles yet. thanks for all the replies. I really do appreciate it. Quote
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